Images overview
Arkindex uses images stored on remote servers through the IIIF Image API version 2.1. To make it easier to handle the references to those images, image URLs are split into two parts: image servers and images. This split makes it easier to handle batches of images that get moved to different URLs or to detect significant issues with a specific server to be reported to their system administrator.
Images and image servers are not managed directly in the Arkindex frontend and typically not needed there, as they are automatically handled by imports and workers. However, they will have to be considered when using the API, administrating an Arkindex instance or using database exports.
Warning
Arkindex does not support version 3 of the IIIF Image API. Using it may lead to subtle issues when viewing elements in the frontend or processing them with workers.
Image servers¶
In Arkindex, an image server represents a subset of images. All images have URLs that start with the same prefix, for example https://example.org/iiif. Arkindex keeps tracks of server-specific settings such as a maximum allowed image width or height, which allows to generate IIIF URLs that do not exceed those limits at scale, without making an image information request for every image.
Updating the URL for a server will update the generated URLs for all of its known images, making it easier to move images to other directories or domain names. We provide additional tools in the administration interface to help with such tasks. You can learn more about managing image servers.
While it is named a server, it does not necessarily represent a real IIIF server, but only the common settings for a set of images. This makes it possible to manage multiple sets of images on the same IIIF server that may have different settings or purely for organizational purposes.
IIIF itself does not have a concept of image servers, so Arkindex attempts to automatically detect the image server for a given image when it is imported. This does not always work and errors may occur during file imports or S3 ingestion. Image servers may be manually created or edited to solve this.
Images¶
An image is a specific path in an image server. Its URL can be built by adding the image server’s URL to the image’s path. For example, an image at image1 in a server at https://example.org/iiif has https://example.org/iiif/image1 as its actual IIIF URL.
Images are unique and can be reused in any element of any project, without any access rights.
Because references to images can be invalid, become stale or be unsupported by Arkindex, images have a state: Checked, Unchecked or Error. Viewing an element that has an image in an Error state will cause a warning to be displayed to report that this image may have issues.
You can view the details of a specific image, as well as all the elements that it belongs to, through the List elements on this image link on any element with an image.